J. Marshall Green

Dissolution of Biopolymers Using Ionic Liquids

Ionic liquids represent a unique class of solvents that offer unprecedented versatility and tunability. Nature has developed a wide variety of materials based upon both proteins and polysaccharides. Many of these materials have unique properties that are a function not only of the material identity but are also largely dictated by processing conditions. Recent work has shown the potential of ionic liquids as solvents for the dissolution and processing of biopolymers. In this research we have expanded upon the limited data available to date using several biopolymers including: silk, chitin, collagen and elastin.

Use of intraoperative fluorescent angiography to assess and optimize free tissue transfer in head and neck reconstruction.

PURPOSE Composite tissue defects in the head and neck region present unique challenges. Definitive head and neck reconstruction of these cases is often complicated by complex 3-dimensional defects that may require multiple flap or chimeric flap procedures. These advanced techniques can have serious repercussions should poor perfusion of the flap cause flap failure, which can be devastating. MATERIALS AND METHODS A retrospective review was completed for those complex reconstructions using free tissue transfers and fluorescent indocyanine green angiography (Lifecell SPY Elite imaging, Lifecell Corporation, Bridgewater, NJ) at Walter Reed National Military Medical Center over a 24-month period. Data analyzed included flap type (myocutaneous, osteocutaneous, or fasciocutaneous), flap success and failure rates, and complications. These also were compared with data from the institution before the study period and the incorporation of SPY technology. RESULTS Sixty-one free flaps, including 11 head and neck flaps, were performed. The head and neck flaps included 1 latissimus, 3 gracilis, 1 vastus lateralis, 4 anterior lateral thigh, and 2 fibular flaps. The overall success rate was 98.4%; 1 flap was lost (1.6%) and 2 flaps developed partial flap necrosis (3.3%). Where SPY Elite was used, there was no unpredicted partial flap necrosis. The only total flap loss was related to a hypercoagulable condition. CONCLUSIONS Free tissue transfer can be technically challenging, especially in complex head and neck reconstruction. An algorithmic approach using SPY Elite imaging aids in pedicle location, angiosomal assessment, anastomotic flow visualization, and cutaneous and osteocutaneous flap perfusion assessment. This objective tool can assist the reconstructive surgeon in avoiding perfusion-related complications and total and partial flap losses, thus improving patient outcomes.

Intraoperative Fluorescence Angiography: A Review of Applications and Outcomes in War-Related Trauma

AIMS In the recent Iraq and Afghanistan conflicts, survival rates from complex battlefield injuries have continued to improve. The resulting war-related wounds are challenging, with confounding issues making assessment of tissue perfusion subjective and variable. This review discusses the utility of intraoperative fluorescence angiography, and its usefulness as an objective tool to evaluate the perfusion of tissues in the face of complex war-related injuries. METHODS A retrospective review of all war-related traumatic and reconstructive cases employing intraoperative indocyanine green laser angiography (ICGLA) was performed. Data analyzed included indication for use, procedure success/failure rates, modifications performed, and perfusion-related complications. Anatomical regions assessed were extremity, head and neck, truncal, and intra-abdominal viscera. The endpoint of specific interest involved the decision for additional debridement of poorly perfused tissue, as based on the ICGLA findings. RESULTS Over a 3-year period, this study examined 123 extremity soft tissue flaps, 41 extremity injuries including amputation and/or amputation revision cases, 13 craniofacial flaps, and 9 truncal/abdomen/gastrointestinal cases in which ICGLA was utilized to assess tissue perfusion and viability. A total of 35 (18.8%) of cases employing ICGLA required intraoperative modifications to address perfusion-related issues. CONCLUSIONS Intraoperative fluorescent angiography is an objective, useful tool to assess various war-related traumatic injuries. This study expands on prior cited indications for ICGLA to include (1) guiding debridement in heavily contaminated wounds, (2) providing improved assessment of avulsion soft tissue injuries, (3) allowing for rapid detection of vascular and/or microvascular compromise in soft tissue and osseous flap reconstructions, (4) reducing and preventing perfusion-related complications in trauma, amputation closures, and reconstruction procedures, (5) contributing to better outcomes in certain complex orthopedic and composite tissue injuries, and (6) enabling improved postoperative wound and reconstruction assessment in those cases of perfusion-related issues that arise within a delayed setting.

Vascularized Osseous Flaps and Assessing Their Bipartate Perfusion Pattern via Intraoperative Fluorescence Angiography

BACKGROUND Large segmental bone and composite tissue defects often require vascularized osseous flaps for definitive reconstruction. However, failed osseous flaps due to inadequate perfusion can lead to significant morbidity. Utilization of indocyanine green (ICG) fluorescence angiography has been previously shown to reliably assess soft tissue perfusion. Our group will outline the application of this useful intraoperative tool in evaluating the perfusion of vascularized osseous flaps. METHODS A retrospective review was performed to identify those osseous and/or osteocutaneous bone flaps, where ICG angiography was employed. Data analyzed included flap types, success and failure rates, and perfusion-related complications. All osseous flaps were evaluated by ICG angiography to confirm periosteal and endosteal perfusion. RESULTS Overall 16 osseous free flaps utilizing intraoperative ICG angiography to assess vascularized osseous constructs were performed over a 3-year period. The flaps consisted of the following: nine osteocutaneous fibulas, two osseous-only fibulas, two scapular/parascapular with scapula bone, two quadricep-based muscle flaps, containing a vascularized femoral bone component, and one osteocutaneous fibula revision. All flap reconstructions were successful with the only perfusion-related complication being a case of delayed partial skin flap loss. CONCLUSIONS Intraoperative fluorescence angiography is a useful adjunctive tool that can aid in flap design through angiosome mapping and can also assess flap perfusion, vascular pedicle flow, tissue perfusion before flap harvest, and flap perfusion after flap inset. Our group has successfully extended the application of this intraoperative tool to assess vascularized osseous flaps in an effort to reduce adverse outcomes related to preventable perfusion-related complications.

Reconstruction of a Post-Traumatic Maxillary Ridge Using a Radial Forearm Free Flap and Immediate Tissue Engineering (Bone Morphogenetic Protein, Bone Marrow Aspirate Concentrate, and Cortical-Cancellous Bone): Case Report

The purpose of this article is to describe reconstruction of the maxillary alveolar ridge by use of a microvascular free flap combined with an immediate tissue-engineered bone graft. This novel surgical technique involved the use of a radial forearm free flap and immediate allogeneic avascular bone graft augmented with bone morphogenetic protein and bone marrow aspirate concentrate. A poly-d,l-lactic acid mesh was used as a containment unit for the bone graft. The patient was successfully treated with a viable radial forearm free flap for soft tissue and regeneration of bone with adequate height and width, which allowed the placement of 3 dental implants with excellent arch coordination. We believe this is the first published case describing such a technique to reconstruct the maxillary alveolus.

A recent case of periorbital necrotizing fasciitis--presentation to definitive reconstruction within an in-theater combat hospital setting.

First described in 1924, necrotizing fasciitis (NF) is a rapidly progressing, severe suppurative infection of the superficial fascia, often associated with vascular thrombosis and necrosis of the overlying skin. Despite advances in medical therapy, the mortality remains high, with rates exceeding 25 to 50% in some studies. Early diagnosis and treatment is paramount in the management of this serious infection and should include wide surgical debridement and drainage of all necrotic tissues, coupled with aggressive parenteral antibiotics. This infectious process has been commonly associated with traumatic events in patients with compromised immune systems, diabetes, chronic steroid use, and alcoholism. The common microbacterial organisms associated with necrotizing fasciitis include Streptococcus pyogenes and Staphylococcus aureus and less commonly, facultative and anaerobic microorganisms. Most cases typically present in the extremities, trunk, and/or groin regions. Although this virulent soft tissue infection can occur within the face and neck areas, cases of isolated periorbital NF have been relatively uncommon. However, head and neck cases of NF have had high associated morbidity and mortality rates. In recent publications, the reported mortality rate for isolated periorbital NF was not insignificant, ranging from 8.5 to 12.5%. The prognosis, morbidity, and mortality rates will be greatly increased in those patients who present late in the infectious phase, have a delay in diagnosis and/or treatment, or who demonstrate extension of this virulent infection into the face, cervical, or sternal/mediastinal regions. An aggressive multimodal approach is required in treating periorbital necrotizing infection, with the main tenant remaining wide and adequate surgical debridement of affected tissues. This difficult clinical situation can create a subsequent challenge with respect to achieving good functional and cosmetic outcomes in those patients with periorbital NF. Delayed reconstruction of the eyelids with skin grafts and/or facial flaps is often required to avoid late complications such as cicatricial lid retraction, lid malposition, exposure keratopathy, and potential loss of vision. We describe a patient who presented to a military combat hospital with a virulent periorbital soft tissue infection. We have outlined his treatment course from the initial presentation through definitive reconstruction.

Synchronous Reconstruction of a Total Mandibulectomy Defect With a Single Fibula Osteocutaneous Free Flap

Osteoradionecrosis (ORN) is a well-known and usually late complication of radiation therapy in the treatment of head and neck cancer. Although the therapy can be life extending, it also produces tissue toxicity in ipsilateral and contralateral tissues in an acute and chronic fashion. In the most severe cases of ORN, such as the one presented in this report, bilateral disease results in the need for total mandibulectomy and creates a tremendous reconstructive challenge. The advent of microvascular surgery and free tissue transfer has caused an evolution of the management protocol for severe ORN cases. This report describes a unique case of total mandibulectomy with synchronous reconstruction using a single vascularized fibula osteocutaneous flap with subsequent dental implant reconstruction and prosthetic rehabilitation.

Facial artery pseudoaneurysm: Challenges of airway management

A patient with recent jaw reconstruction presented for treatment of postoperative oropharyngeal hemorrhage. Asleep nasal fiberoptic intubation was attempted, but a rare and unanticipated complication ensued: rupture of right facial artery pseudoaneurysm. The difficult airway algorithm was followed up to the point of surgical airway. While nasal or oral fiberoptic intubation is often perceived as the safest approach for management of a difficult airway, we discuss alternative treatment strategies for patients with a facial pseudoaneurysm. Such alternatives include preoperative angiographic endovascular embolization of the vessel(s) feeding the pseudoaneurysm, and/or elective tracheostomy.

Immediate Microsurgical Bone and Nerve Reconstruction in the Irradiated Patient: A Case Report

Microsurgical reconstructive techniques have revolutionized the treatment of large head and neck defects. These defects were once forever life altering because of the considerable morbidity to both the form and function of the patient. As time has progressed, microsurgical technique has improved dramatically and has become institutionalized in our training programs. Free flap outcomes in head and neck reconstruction have improved dramatically, and optimization of these outcomes is now key. One overlooked area has been neurosensory reconstruction. In our practice we have focused on this detail, which has proved to be quite important to the patient. This case report details one such case in which a mandibular resection was performed to treat osteoradionecrosis. We, as the reconstructive team, elected to perform a double-barrel fibular free flap procedure with simultaneous inferior alveolar nerve reconstruction using a 70-cm processed nerve allograft. Normal neurosensory function returned in this patient. As the state of the art advances with continued successful osseous and soft tissue reconstruction in the head and neck, we propose concomitant neurosensory functional reconstruction always be considered.